Abu Bakr

Umar

Uthman

Third Successor. Didn't have good control of outer regions. There were delegates for the regions. He had them report and they were to take letters back to their regions. Letters ordered the delegates' deaths. They returned mad. Mobbed and murdered Uthman.

Ali

Declared himself fourth successor. Cousin and son-in-law of Muhammad. Didn't seem to be too concerned about Uthman's murder, btw. Muawiya and Aisha (Muhammad's widow) contested but were fighting amongst themselves. They were going to battle but didn't. Battle of camel. Aisha gave up. Ongoing feud with Muawiya.